Ice cube maker and control mechanism therefor



Dec. 25, 1956 D. E. M LEOD ICE CUBE MAKER AND CONTROL MECHANISM THEREFOR Filed July 1, 1950 3 Sheets-Sheet 2 INVENTOR. wmmxd BY $4M Q01" Dec. 25, 1956 D. E. MacLEOD 2,775,098

ICE CUBE MAKER AND CONTROL MECHANISM THEREFOR Filed July 1, 1950 3 Sheets-Sheet 3 INVENTOR.

United States Patent R ICE CUBE MAKER AND CONTROL MECHANISM THEREFOR David Earle MacLeod, Syracuse, N. Y., assignor to Carrier Corporation, a corporation of Delaware Application July 1, 1950, Serial No. 171,593

19 Claims. (Cl. 62-7) This invention relates to devices for forming small pieces of ice, and more particularly to a. device for forming ice cubes for use in restaurants, bars, hotels, or similar places in which a large quantity of small pieces of ice is consumed within a short period of time. The term cube is employed herein to define a small piece of ice of any desired geometrical configuration and is not limited to a piece of ice of specific geometrical contour.

The chief object of the present invention is to provide an ice cube maker in which the ice forming elements are designed to form separate pieces of ice of predetermined size and geometrical contour, the separate pieces of ice being automatically melted from the ice forming elements and transferred to a storage chamber.

A further objectis to provide an ice cube maker adapted to form transparent separate pieces of ice in vertically extending tubes from a stream of water flowing through the tubes, and including control mechanism for rendering the machine wholly automatic in operation, whereby the ice forming and harvesting operations are conducted cyclically until a desired quantity of ice is formed and then the operation of the machine is discontinued, operation beginning again automatically when a predetermined portion of the formed pieces is consumed.

A still further object is to provide an ice cube maker adapted to form transparent separate pieces of ice in vertically extending tubes from a stream of Water flowing through the tubes in which the control mechanism therefor is actuated by flow of water in a different path when passage through the tubes is retarded by formation of ice.

A still further object is to provide a method of manufactnring ice in separate pieces. Other objects of my invention will be readily perceived from the following description.

This invention relates to an ice cube maker which comprises in combination an ice forming element, means to pass a stream of water in contact with the ice forming element, a refrigerating system including an evaporator in contact with the ice forming element, means to harvest ice formed in said element and a control for automatical- 1y supplying heated refrigerant vapor to the evaporator in the same direction of flow through the evaporator as the direction of flow of liquid refrigerant therethrough during the ice forming operation.

This invention further relates to an ice cube maker which comprises in combination a hollow ice forming element, means to pass a stream of water through the element, second means to receive at least a portion of a stream of water when its flow through the element is retarded by ice formation, a refrigerating system including an evaporator in contact with the ice forming element, means to harvest formed ice, a thermal responsive control for regulating ice formation and ice harvesting, a thermal responsive member connected to the control disposed in heat exchange relation with water in said second means and responsive to the temperature of such water to actuatethe control to discontinue ice formation and to begin ice harvesting.

2,775,098 Patented Dec. 25, 1956 This invention further relates to a method of forming ice in which the steps consist in directing a stream of water in a first path in contact with an. ice forming element, refrigerating the ice forming element to form ice, then when formation of ice retards flow of water in the first path directing at least a portion of the stream of water in a second path to discontinue ice formation and to begin ice harvesting.

The attached drawings illustrate a preferred embodiment of my invention in which Figure 1 is a front view partly in elevation and partly in section of the device of the present invention,

Figure 2 is a plan view, the casing being removed, of the device shown in Figure 1;

Figure 3 is a view in elevation, the casing being removed, of one side of the device;

Figure 4 is a view in elevation, the casing being removed, of the opposite side of the device;

Figure 5 is a diagrammatic view of the refrigeration circuit;

Figure 6 is a diagrammatic view of the water circuit;

Figure 7 is a diagrammatic view of the electrical circuit for the control;

Figure 8 is an isometric view of the water distributor;

Figure 9 is a sectional view of the overflow well;

Figure 10 is a sectional view of the waterheader;

Figure ll is a diagrammatic view similar to Figure 5 illustrating a modified refrigeration circuit; and

Figure 12 is a diagrammatic view similar to Figure 7 illustrating a modified control system.

Referring to the drawings, there is disclosed an ice cube maker which includes a machine compartment 2 and an insulated ice storage compartment or bunker 3 placed below the machine compartment. Preferably these compartments are formed as separate elements being attached to one another when the ice cube maker is assembled at the place of use in order that the machine compartment may be utilized with bunkers of different capacity. It will be understood of course that the machine may be formed as a single unit if desired.

Machine compartment 2 includes standards 4} and braces 5 from supporting framework. Decorated removable metal sheets 6 are attached to the frame to form the Walls of the machine compartment. Compartment 2 may be insulated to prevent condensation on the surfaces of sheets 6. Storage compartment 3 is provided with an opening 7 through which ice enters the storage water supply system, the controls, and an electrical circuit connecting the controls.

The ice forming member 9 includes a plurality of vertically extending tubes 10 formed of stainless steel, tubes 16 having a plurality of copper bands or rings 11 placed about the exterior thereof, the bands 11 being spaced from one another longitudinally on the tubes. The copper bands may be preformed and secured to the tubes by a friction fit or, if desired, molten copper may be sprayed on the tubes to form the bands, or, the tubes may be plated with copper bands. Tubes 10 are assembled in two parallel rows and on overflow trough 12 is placed between the parallel rows for a purpose hereinafter explained.

Each tube 10 is formed from a single sheet of metal in such manner that its side wall 13 inclines downward and outward substantially uniformly throughout the length of the tube so that the opening 14 in the bottom of the tube is greater in area than the opening 15 in the top of the tube. Two adjacent side walls have flanges extending outwardly therefrom, the flanges being pressed together and welded, for example, to form the tube. The top of each tube is formed with a pitcher lip 16.

The evaporator 17 of the refrigeration system is formed of a plurality of coils 18, 19', 20, 21; coils18, 19 being secured to the bands 11 on opposite sides of the first row of tubes while coils 20-, 21 are secured to the bands 11 on opposite sides of the second row of tubes 10. If desired, coils 18, 19, 20, 21 may be flattened on one, side to assure a greater area of contact with bands 11.

The ice forming member 9 is more fully described and claimed in the copending application of Carlyle M. Ashley, Serial No. 171,621 filed July 1, 1950 to which reference is made for a more complete description.

Below the ice forming rnemher-9 is an inclined deflector or guide 22 on which the pieces of ice fall from tubes 19 during the harvesting operation and down which the ice slides into openings 7 of bunker 3, Deflector 22 may be a suitable screen or grid to permit water to pass therethrough while. preventing passage of ice cubes. Water from the tubes passes throughdeflector 22 into a sump as hereinafter explained.

Referring to Figure 5, there is shown the refrigerating and harvesting circuit of the ice cube maker. Such circuit includes a semihermetic.compressor motor unit, the compressor 23 being actuated by motor 29. Compressor 28 is connected by dischargeline 30 to condenser 31, preferably water cooled, although if desired, an air-cooled condenser may be employed. Liquid line 32.includes two capillary tubes 33, 34 adapted to serve as expansion means to regulate supply of liquid refrigerant to evaporator 17.- A strainer and drier may be placed in line 32 between condenser 31 and capillaries 33, 34. Other expansion means may be employed if desired. Capillary 33 supplies refrigerant to coils 18, 19; capillary 34 supplies refrigerant to coils 20, 21. Each capillary as shown in Figure 5 is connected to a return bend 36 at approximately the central point between the two coils to which it supplies refrigerant. This is important in my invention to iassure adequate supply of refrigerant to each of the cor s. Refrigerant passes from each of coils 18, 19, 20, 21 into a return header 37 for return to compressor 28. Header 37 is connected by line 38 to accumulator 3?. A line 40 connects accumulator 39 to a second accumulator 41. Accumulator 41 is connected by suction line 42 to the compressor 28. Accumulator 41 is also connected by a drain line 43 tomotor 29 to permit oil and liquid refrigerant in accumulator 41 to pass to the motor. Line 43 must be as short and as friction-free-as possible to offer less resistance to refrigerant flow than the main line 42. This 18 an important feature since any liquid refrigerant draining from, accumulator 41 with the oil is returned to compressor 28 over the heated coils of the motor, thus flashing the refrigerant to assure that gaseous refrigerant only returns to thecompressor, thereby avoiding excessive wear and tear of compressor elements.

Capillaries 33, 34, are wrapped about accumulator 39 in heat exchange relation therewith. In addition, the capillaries maybe placed in heat exchange relation with line 40 if desired.

A heated refrigerant vapor line 44 connects the top of the condenser 31 with a supply header 45 connected by lines 46 to coils 18, 19, 20, v21. A solenoid valve 47 is placed in line 44 and closes the same to the passage of heated refrigerant vapor. It will be appreciated line 44 may connect header 45 with the compressor 28 or line 30 if desired, to permit heated refrigerant vapor to be supplied to coils 13, 19, 20, 21 to melt formed pieces of ice from the interior walls of tubes 10.

In Figure 6, the water distribution system is shown diagrammatically. Line 50conducts'water from a source of supply (notshown) to a sump or reservoir 51 placed inthebottom of machine compartment 2 below tubes 10 and deflector 22. A floatvalveSZregulates the level; of

water in sump 51. A drain line 53 may bleed a minor amount of water continuously from sump 51 thereby pre venting concentration of minerals in water in the sump. A pump P circulates water from sump 51 through lines 54 to water headers 55 placed above the rows of tubes 10.

Water from headers 55 is discharged against distributors 56 placed within tubes 10, the distributors directing or guiding the water toward or against the interior walls of tubes 10. The water flows through tubes 10 in contact with the interior walls thereof, through deflector 22, and returns or falls into sump 51. The water, of course, is cooled by its passage through therefrigerated tubes 10 to substantially freezing temperature. Thuscooled or chilled water not formed into ice is continuously recirculated through tubes 10 to reduce the timerequired for ice formation and to increase the capacity of the machine.

Water header 55 as shown in Figure 10, consists of a horizontally extending pipe 57, pipe 57 having a closed end 58. A series of distributing tubes 59 extend downward from pipe 57 to distribute water within the tubes 10. One pipe or tube 59 is provided for each ice forming tube 10 to assure adequate distribution of water to each tube 10. The first and second tubes 59'of the series extend substantially flush with interior wall60 ofpipe 57. Subsequent tubes or pipes 59 of the series extend inward from the interior wall 60, the extended portion 61 being cut away as shown at 62 to intercept water from the stream flowing into pipe 59. The last tube of the series is also substantially flush with the interior wall 60 of pipe 59.

A distributor 56 is present in each tube 10. Distributor 56 includes a plate portion 63 against which the stream of water from pipe 59' is directed. Protuberances 64 extend from opposite sides of plate 63 to space the plate from the interior wall of'tube 10. Legs 65 extend upward from the remaining side of-plate 63. Legs 65 terminate in flanges 66 adapted to rest upon the end of tube 10. Each leg 65 includes a portion 67' extending inward and upward from plate 63, a second portion 68 connected to portion 67 extending upward and outward therefrom, and a third portion 70 connecting portion 68 with flange 66. This construction of the legs prevents water climbing upward along the retaining members thereof to the top. of tube 10.

The passage of Water through tubes 10 is ultimately prevented or retarded by the formation of ice in the tubes. The tubes overflow, the lip 16 on each tube directing the water into trough 12. from whence it takes a different path to return to sump 51. The overflow water in trough 12 drains therefrom through a line v71 connected to an S-shaped pipe arrangement 72 which forms an overflow well. Water from. well 72 returns to siunp 51 through line 73. Well 72 contains an open leg 74 which is connected to line 71 as shown in Figure 9. At the top of a second leg 75 is provided an orifice 76 which prevents siphoning. Leg 74 of well '72 is clamped in contact with the heated refrigerant vapor line 44 of the refrigeration system for a purpose hereinafter explained.

To control the refrigeration and harvesting cycles, a wide dilferential thermostatic control 80v is provided which includes a switch lever 81. (refer to Figure 7) actuated by a thermal responsivesystem including a bellows 82 connected to the switchleverfil and acapillary tube 83 connecting bellows 82 with a bulb 84; The thermal responsive system contains a temperature responsive fill. Bulb 84 is placed in well 72 and a portion 83'. of capillary tube 83 is placed in contact with suction line 42. Preferably portion 83' is placed in contact. with the portion of suction line 42 adjacent compressor 28:to assure that it is affected as little as possible by liquid refrigerant or wet liquid vapor flooding back to thecompressor 28. When water overflows from trough 12 into well 72 it displaces water present in well 72 and gradually cools bulb 84 until it becomes'the coldest point of the thermal responsive system, thereby governing thermostat 80 from such point. Switch lever 81 is accordingly moved from a first position to a second position to discontinue operation of pump P and to actuate the solenoid S of valve 47, to open the heated refrigerant vapor line 44 to supply heated refrigerant vapor to coils 18, 19, 20, 21 to thaw formed pieces of ice from the interior walls of tubes 10.

During the harvesting operation, the heated refrigerant line 44 warms the water in well 72 so that the controlv point shifts to portion 83' of capillary tube 83 which is in contact with the suction line 42. The temperature of the refrigerant passing through the suction line is below the cut-in point of thermostat 80 so long as ice remains in tubes 10. As the last piece of ice is removed from tubes 10, temperature in the suction line rises to the cutin point of the thermostat, the thermostat then being actuated to start pump P and to discontinue current flow to solenoid S, thereby closing valve 47 and resuming the refrigeration cycle.

A second thermostat control 87 is provided to discontinue operation of the refrigeration system and the pump when a desired quantity of ice is present in the bunker. Control 87 includes a switch lever 88, a bellows 89 connected by capillary tube 90 to a bulb 91 placed in bunker 3 adjacent the top thereof. A suitable fill is present in bellows 89, capillary tube 9i) and bulb 91. When a predetermined quantity of ice is present in bunker 3, bulb 91 is cooled, thereby actuating thermostat 87 to open the circuit to control 89 and the compressor 28, discontinuing operation of the system. Upon removal of ice from bunker S, bulb 91 warms to a point at which thermostat 87 is again actuated to close the circuit, permitting supply of current to actuate the compressor and control 80.

Preferably a high pressure cut-out control 92 is provided as a safety control, control 92 being responsive to head pressure to shut down the system upon the occurrence of a pressure so high that it might harm elements of the system. In Figure 7, I have shown the electrical circuit connecting the various controls and actuating elements of the device. A manual double pole single-throw switch or single pole, single throw switch 93 is employed to actuate the device. The remaining elements are connected in the circuit as shown.

As previously described, a water-cooled condenser 31 is employed for the refrigeration system. Condenser 31 may be connected by a line 94 to line 50 to supply water to condenser 31. Preferably an automatic control valve 95 is placed in line 94 and is connected by line 96 to compressor 28 to permit head pressure to be applied to actuate valve 95. The water passing through condenser 31 is thus regulated in response to head pressure.

Considering the operation of the device, manual switch 93 is closed thereby actuating motor29 to operate compressor 28 of the refrigeration system and pump Pto supply water from sump 5'1 to header 55 for distribution in tubes 1'3. Water flows downwardly through distributing tubes 59 to each tube 10 and strikes distributor 56 therein, distributor 56 directing the water toward the interior wall of the tube. Water flows downward over the interior wall of each tube 10 and returns to sump 51. The walls of tubes 10 are refrigerated in spaced portions by means of coils 18, 19, 20, 21 and the copper bands 11. Thus water flowing through the tubes is cooled and within a short time separate pieces of ice begin to form within the tubes 10 adjacent the refrigerated portions thereof. As ice formation continues, within a short time the spaced pieces of ice present in the tubes are so large as to impede or retard passage of cooled water therethrough so that the tubes overflow into trough 12.

Water from trough 12 flows through line 71 into overflow well 72 displacing the Water therein and cooling bulb 84 so that it becomes the control point. When a predetermined low point is reached thermostat 80 is actuated, moving switch lever 81 from a first position to a second position, discontinuing operation of pump P and passage of water to tubes 10, and actuating solenoid S g to move valve 47 to an open position permitting heated refrigerant vapor to How into coils 18, 19, 20, 21 to melt the formed pieces of ice from the interior walls of tubes 10, simultaneously water in well 72 being in heat exchange relation with line 44 is heated to shift the control point of thermostat to capillary tube portion 83.

Capillary tube portion 83 does not become sufficiently warm to actuate thermostat 80 until all ice is removedv from tubes 10 since it is in heat exchange relation primarily with liquid refrigerant condensed by heat exchange of the heated vapor with the formed ice in tubes 10.

Ice drops from tubes 10 by gravity upon deflector 22 and slides into bunker 3 through openings 7. After the last piece of ice is removed from the tubes, the hot vapor passing into suction line 42 raises the temperature of the fill in capillary tube portion 83', thereby actuating thermostat 80 to move from its second position to its first position closing the solenoid valve 47, resuming refrigeration of tubes 10, and starting pump P to supply water from sump 51 through tubes 10.

The refrigerating and harvesting cycles repeat automatically until a predetermined quantity of ice is formed. When a predetermined quantity of ice is collected in bunker 3, thermostat 87 is actuated to break the electrical circuit, discontinuing operation of the machine. Upon removal of ice from bunker 3, thermostat 87 is again actuated to begin operation of the machine.

In Figure 11, there is shown diagrammatically a modified refrigeration system. The system shown in Figure 11 is generally similar to the system shown in Figure 5. It diifers therefrom in that the hot gas or heated refrigerant line 44 is wrapped about compressor 28 in order that additional heat might be removed from the compressor and supplied to the refrigerant vapor being forwarded to the evaporator 17 to aid in harvesting pieces of ice in tubes 10. It will be noted too that in this modified refrigeration system, accumulator 40 may be eliminated since the additional heat supplied to the refrigerant vapor assures that no liquid refrigerant returns from evaporator 17 to compressor 28.

In Figure 12 I have shown a modified electrical circuit in which a three-point selector switch is employed in place of the manual double pole single throw switch 93. In this case, it will be noted that line L1 is connected to thermostat 87. The three positions: of switch 110 permit the machine to be operated or its operation to be discontinued, or pump P to be operated without operation of the refrigeration system. This is desirable to permit pump P to be operated for cleaning purposes to pump water through tubes 19 to clean the interior of the tubes.

The present invention provides an economical automatically operable ice cube maker. Use of this machine greatly reduces the cost of ice to a consumer. The machine is designed tooperate automatically in response to demand for pieces of ice. The time required for forming and harvesting a desired quantity of ice varies of course with ambient temperature and the temperature of the water supplied to the ice forming element. The present invention permits the water supplied to the ice forming element to be pre-cooled, thereby reducing the length of the refrigeration cycle and greatly increasing the capacity of the machine.

While I have described a preferred embodiment of my invention it will be understood my invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. In an ice cube maker, the combination of a hollow ice forming element, a refrigeration system including a compressor, a condenser, a discharge line connecting the compressor and the condenser, an evaporator, a liquid line connecting the condenser and the evaporator, expansion means disposed in the liquid line and comprisingacapillary tubes, a suction line connecting. the evapow rator and the compressor, a first accumulatoranda secondv accumulator placed. in the suction line and said capillary tubes being disposed about the first accumulator, the evaporator in the refrigeration systembeing placed in .contact with. the ice forming element, means to pass a stream of Waterfor ice formation through the element, a line connecting the evaporator with a portion of the refrigeration system containing heated refrigerant vapor, means in said line normally closing the line, opening of said means permittingheated refrigerant vapor to pass tothe evaporator to harvest ice formed in said element.

2. An ice cubemaker according to claim 1 in which the evaporator includes four separate coils, two adjacent coils being connected by a return bend, theother two coils being connected by a second return bend, one of said capillary tubes being connected substantially at the central point of one of said return bends to supply refrigerant to two of the coils in substantially equal quantities, the

other of said capillary tubes being connected substantially at the central point of the other'of said return bends to supply refrigerant to two of the coils in substantially equal quantities, and a header is provided connected to the heated refrigerant vapor line, said header being connected to each coil to supply heated refrigerant vapor to the coils.

3. In an ice cube maker, the combination of an ice forming element, means to pass a stream" of water in contact with the ice forming element, a refrigeration system including an evaporator in contact with the ice forming element, means to harvest ice formed in said element, a control for automatically discontinuing supply of liquid refrigerant to the evaporator and for supplying heated refrigerant vapor to the evaporator in the-same direction of flow through the evaporator as the direction of liquid refrigerant therethrough during the ice forming operation and a second control for discontinuing operation of the refrigeration system upon formation of a desired quantity of ice, the first control being actuated in response to a change in the direction of flow of at least a portion of the stream of water to begin the harvesting operation and in response to a predetermined increase in temperature in the suction line of the refrigeration system to discontinue the harvesting operation and to begin ice formation.

4. In an ice cube maker, the combination of a casing, a plurality of ice forming tubes placed adjacent one another in said casing, a plurality of spaced bands having a heat conducting value greater than the tubes placed about the exterior of each tube, a sump in thecasing, means to pass a stream of Water from the sump through the tubes, the stream of water returning to the sump, a refrigeration 'system including an evaporator placed in heat exchange relation with the bands serving to form spaced pieces of ice from the water stream Within the tubes, formation of ice within the tubes retarding flow of water therethrough, harvesting means, an S-shaped overflow well to receive at least a portion of a stream of water when its flow through the tubes is substantially retarded by ice formation, a leg of the well having an orifice in its upper portion to prevent siphoning of water in the well and means for actuating the harvesting means in response to the temperature of water flowing through the overflow well, a storage chamber for pieces of ice placed in a plane below the bottoms of the tubes, and means to direct pieces of ice passing from the tubes to the storage chamber.

5. In an ice cube maker, the combination of a hollow ice forming element, means to pass a stream of water through the element, second means to receive at least a portion of a stream of water when its flow through said element is retarded by ice formation, a refrigeration systern including an evaporator in contact with'the ice forming element, means to harvest formed. ice, athermal responsive control for.regulating.ice;formation. andice har.vesting, a thermal responsive member connected to the control disposed in heat exchange relation with water in said second means and responsive to the temperature of such water to actuate the control to discontinue ice formation and to begin ice harvesting and a second thermal responsive member connected to the control disposed in heatexchange relation with the suction line and responsive to the'temperature therein to actuatethe control to discontinue ice harvesting and to begin ice formation.

6. An ice cube maker according to claim 5 in which a capillary line connects the control and the first thermal responsive member, a portion of said capillary line servmg as said secondthermal responsive member being placed in contact with the suction line of the refrigeras tion system.

7. In an ice cube maker, the combination of .a hollow ice forming element, meansto pass a streamof water through the element, second" means to receive at least a portion of the stream of Water when its flow through the element is retarded substantially by ice formation in the element, a refrigeration system including an evaporator in contact with the ice forming element, a heated refrigerant line connecting the discharge line of the refrigeration system and the evaporator, a control for regulating ice formation and ice harvesting, a thermal responsive member, a capillary tube connecting the thermal responsive member and the control, a portion of the capillary tube being placed in heat exchange relation withthe suction line of the refrigeration system, said thermal responsive member being disposed in heat exchange relation with water in the second means and responsive to the temperature of such water to actuate the control to discontinue ice formation and to begin ice harvesting, said heated refrigerant line being placed in heat exchange relation with the'second means to increase gradually temperature of water in the second means during the harvesting operation whereby actuating of the control shifts to the portion of the capillary tube in contact with the suction line, the control remaining in harvesting position until all ice has been removed from the element and then again actuating the system to begin ice formation.

8. An ice cube maker according to claim 7 in which the control is a wide differential thermostat, said thermostat being actuated by the thermal responsive member to discontinue ice formation and to begin ice harvesting, thereafter being regulated by the capillary line portion in contact with the suction line so that upon a predetermined increase in temperature in the suction line indicating all ice has been removed from the element, the control functions to discontinue harvesting and to begin ice formation.

9. In a method of forming ice, the steps which consist in directing a stream of water in a first path in contact with an ice forming element, refrigerating the ice forming element to form ice, then, when formation of ice substantially retards flow of water in the first path, directing at least a portion of the stream of water in a second path to actuate a control member to discontinue ice formation and to'begin ice harvesting, harvesting formed ice, and upon increase in temperature in the suction line of'the refrigeration system to a predetermined point, again actuating the control member to discontinue harvesting and to begin ice formation.

10. In a method of operating an ice cube maker, the steps which consist in directing a stream of water in contact with an ice forming element, supplying liquid refrigerant in a predetermined path in contact with spaced portions of the ice forming element to form spaced pieces of ice, then, when formation of ice is completed to a predetermined degree, discontinuing the supply of liquid refrigerantto the element and supplying heated refrigerant v-aportto the element through the same path to harvest.

the formed ice, simultaneously discontinuing the flow of water in contact with the ice forming element, automatically repeating the operation when all of the ice is harvested, directing at least a portion of the stream of water in a second path when flow of water in contact with the ice forming element is retarded substantially to actuate a control member to begin the harvesting operation and to discontinue ice formation, and, upon an increase in temperature in the suction line to a predetermined degree, discontinuing harvesting and beginning ice formation.

11. In an ice cube maker, the combination of a casing, a plurality of ice forming tubes placed adjacent one another in the casing, a plurality of spaced bands havi-ng a heat conductive value greater than the tubes placed about the exterior of each tube, a sump in the casing, a pump to pass a stream of water from the sump through the tubes, the stream of water returning to the sump, a refrigeration system including a compressor, a condenser, expansion means and an evaporator disposed in a closed circuit, the evaporator of the refrigeration system being placed in contact with the bands, a line connecting the evaporator with the discharge line of the circuit, means for normally closing said line, a control for actuating said means to permit heated refrigerant vapor to pass to the evaporator to harvest ice formed in the tubes, formation of ice in the tubes retarding passage of water therethrough, and an S-shaped overflow well to receive at least a portion of the stream of water when its fiow through the tubes is substantially retarded by ice formation, a leg of the well having an orifice in its upper portion to prevent siphoning of water in the well, said control being actuated in response to the temperature of the water in the overflow well.

12. In an ice cube maker, the combination of a casing, a plurality of stainless steel ice forming tubes placed adjacent one another in the casing, a plurality of spaced copper bands placed about the exterior of each tube, a sump in the casing, a pump to pass a stream of water from the sump through the tubes, the stream of water returning to the sump, a refrigeration system including a compressor, a condenser, a discharge line connecting the compressor and the condenser, an evaporator, a liquid line connecting the condenser and the evaporator, expansion means placed in said liquid line, and a suction line connecting the evaporator with the compressor, the evaporator being placed in heat exchange relation with the bands and serving to form spaced pieces of ice from the water stream flowing through the tubes, formation of ice within the tubes retarding flow of water therethrough, a line connecting the evaporator with the discharge line, a solenoid valve in said connecting line, the solenoid valve when opened permitting flow of refrigerant vapor to the evaporator, means for directing the water in a different path as flow of water through the tubes is retarded substantially, a control for actuating the solenoid valve in response to the temperature of water flowing through the different path, said control being responsive to an increase in the temperature in the suction line to close the solenoid valve and to start ice formation, a storage chamber placed in a plane below the bottom of the tubes for pieces of ice and means to direct pieces of ice falling from the tubes to the storage chamber.

13. In an ice cube maker, the combination of a casing, a plurality of stainless steel ice forming tubes in said casing placed adjacent one another, a plurality of spaced copper bands placed about the exterior of each tube, a sump in the casing, a pump to pass a stream of water from the sump through the tubes, the stream of water returning to the sump, means to receive at least a portion of the stream of water when its flow through the tubes is retarded substantially by ice formation, harvesting means, a single thermal responsive control for regmlating ice formation and ice harvesting, a thermal responsive member connected to the control disposed in heat exchange relation with water in said first means, and responsive to the temperature of such water to actuate the control to discontinue ice formation and to begin ice harvesting, a storage chamber for pieces of ice placed in a plane below the bottom of the tubes, means to direct pieces of ice falling from the tubes through the storage chamber and means in said storage chamber for discontinuing operation of the refrigeration system when a predetermined quantity of ice is formed.

14. An ice cube maker according to claim 13 in which the thermal responsive control comprises a wide differential thermostat connected to the thermal responsive member by a capillary line, at least a portion of said capillary line being placed in contact with the suction line of the refrigeration system, said thermostat being actuated by the thermal responsive member to discontinue ice formation and to begin ice harvesting, thereafter being regulated by the capillary line portion so that upon an increase in temperature in the suction line indicating all ice has been removed from the tubes, the control is actuated to discontinue harvesting and to begin ice formation.

15. In a refrigeration system, the combination of a compressor, a condenser, a discharge line connecting the compressor and the condenser, an evaporator including a plurality of coils placed in heat exchange relation with ice forming elements, a liquid line connecting the evaporator and the condenser, capillary tubes in the liquid line regulating supply of liquid refrigerant to the coils, a first accumulator connected to the evaporator, a second accumulator, a line connecting the second accumulator to the first accumulator, said line being disposed in heat exchange relation with the capillary tubes, a line connecting the second accumulator with the compressor, the capillary tubes being placed in heat exchange relation with the first accumulator.

16. A refrigeration system according to claim 15 in which the condenser is water cooled, a valve is provided to regulate passage of water through the condenser, the valve being responsive to head pressure of the refrigeration system, and means are provided to place the cooling water after passage through the condenser in heat exchange relation with the compressor.

17. In a refrigeration system, the combination of a motor-compressor unit, a condenser, a discharge line connecting the compressor and the condenser, an evaporator, a liquid line connecting the evaporator and the condenser, expansion means in the liquid line, a first accumulator connected to the evaporator, a second accumulator connected to the first accumulator, a suction line connecting the second accumulator with the compressor, and a drain line connecting the second accumulator with the unit motor whereby liquid refrigerant returned to the unit from the accumulator is flashed by passage over the motor.

18. An ice cube maker according to claim 7 in which the second means comprises an S-shaped overflow Well, one leg of the well being placed in heat exchange relation with the heated refrigerant line, the thermal responsive member extending within said leg, the second leg of the well having an orifice in its upper portion to prevent siphoning of water in the well.

19. In an ice cube maker, the combination of a hollow ice forming element, means to pass a stream of water through the element, an S-shaped overflow well to receive at least a portion of the stream of water when its flow through said element is substantially retarded by ice formation, a refrigeration system including: an evaporator in contact with the ice forming element, a heated refrigerant line connecting the discharge line of the refrigeration system and the evaporator, a control for regulating ice formation and ice harvesting, a thermal responsive member, a capillary tube connecting the thermal responsive member and the control, a portion of the capillary tube being placed in heat exchange relation with the suction-J1me 1 of the refrigeration. system, saidthermal responsive member being placed .in one leg of the, S-

shaped overflow well. in heat exchange relationawith waterin said leg. and being responsive to the temperature of said water to actuate the control to discontinue ice for? mation and-to begin ice harvesting, saidheated refrigerant line'beingplaced in heat exchange relation with said leg to increase gradually the temperature of the Water in said leg during the harvestingoperationwhereby regulation of thCnCOIltI'Ol shifts to the portion of the capillary tube in contactwith the suction line, the control being actuated to discontinue ice harvesting and to begin ice formation responsive-to the temperature of the portion of the capillarytubedn contact With the. suction line when a predeterminedincreasein temperatureoccurs in the suction line theflsecondtlegof tl1e-.well havingan orifice in its upper portion toprevent siphoningof water in the Well.

References Cited in the file of this patent UNITED STATES PATENTS 2,009,283 Warner July-23, 1935 12 Mufily Jan. 31, Monti Oct. 29, Wiggins] July 14, Wolfert Feb. 22, Mufily Feb. 6, Williams Mar. 12, Smith Aug. 6, Carter Oct. 22, Lucia Feb. 2 Smith June 15, Zearfoss Nov. 1, Field Nov. 22, Mufily Feb. 7, Gerteis June 6, Field Sept. 19, Leeson ,Oct. 10, Maseritz: Oct. 17, Leeson Apr. 17, Field Feb. 26, Grandia Apr. 22,

McCloy Sept. 2, 

